@article{ref1,
title="The post concussion syndrome",
journal="Industrial medicine and surgery",
year="1972",
author="Elia, J. C.",
volume="41",
number="5",
pages="23-31",
abstract="<p>[Abstract unavailable]</p><p>Language: en</p>",
language="en",
issn="0019-8536",
doi="",
url="http://dx.doi.org/"
}